1. Field of the Invention
The present invention relates to an apparatus for quantitatively extruding food material, and more particularly to an apparatus for quantitatively extruding a mixture of food materials, as for example, a vegetable salad or a fruit salad, which are mixtures of pieces of vegetables, fruit and/or meat that is not uniform in shape, and a dressing, into a bread, such as a croissant.
2. Description of Prior Art
Japanese Patent Publication No. 39-21968 discloses an apparatus for quantitatively extruding paste material, in which two opposed rollers, each provided with a plurality of accurate recesses on the peripheies thereof, are rotated step by step, each pair of opposing recesses forming at each step a cylindrical space, whereby the paste material is enclosed in the space, and is then extruded by a piston.
In this apparatus the rollers can be rotated only after the piston is withdrawn, and moreover, it is necessary to introduce air into the temporarily formed cylindrical space to avoid vacuum and to enable the piston to be smoothly retracted therefrom.
Along with the rotation of the rollers, the introduced air is brought into the hopper and is increasingly enclosed together with the food material in the cylindrical space, which leads to inaccurate measurements of the food material.